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| United States Patent |
5,187,251
|
|
Jachmann
, et al.
|
February 16, 1993
|
Curable organopolysiloxanes having epoxy groups, methods of synthesizing
them and their use as curable coating materials with abhesive properties
Abstract
Organopolysiloxanes are disclosed which contain, aside from methyl groups,
alkyl groups with 1 to 20 carbon atoms, aryl groups or aralkyl groups,
epoxy groups which are linked over Si--C bonds to silicon atoms of the
polysiloxanes, and R.sup.3 OH groups, R.sup.3 being a divalent alkylene
groups with 3 to 11 carbon atoms. The organopolysiloxanes have good
compatibility with photoinitiators and adhesion and release properties
which can be adjusted for the intended application by coordinating the
long chain alkyl groups, the epoxy groups and the --R.sup.3 OH groups.
| Inventors:
|
Jachmann; Jurgen (Herne, DE);
Weitemeyer; Christian (Essen, DE);
Wewers; Dietmar (Bottrop, DE)
|
| Assignee:
|
Th. Goldschmidt AG (Essen, DE)
|
| Appl. No.:
|
730347 |
| Filed:
|
July 15, 1991 |
Foreign Application Priority Data
| Current U.S. Class: |
528/15; 427/387; 427/389.7; 428/429; 428/447; 528/27; 528/29 |
| Intern'l Class: |
C08G 077/06 |
| Field of Search: |
528/15,27,29
427/387,389.7
428/447,429
|
References Cited
U.S. Patent Documents
| 4310469 | Jan., 1982 | Crivello | 260/446.
|
| 4313988 | Feb., 1982 | Koshar et al. | 428/40.
|
| 4394403 | Jul., 1983 | Smith | 427/42.
|
| 4639321 | Jan., 1987 | Barrat et al. | 252/8.
|
| 4822687 | Apr., 1989 | Kessel et al. | 528/15.
|
| 4959404 | Sep., 1990 | Nakane et al. | 528/29.
|
| Foreign Patent Documents |
| 0334068 | Sep., 1989 | EP.
| |
| 0355381 | Feb., 1990 | EP.
| |
| 0391162 | Oct., 1990 | EP.
| |
Primary Examiner: Marquis; Melvyn I.
Attorney, Agent or Firm: Anderson Kill Olick & Oshinsky
Claims
We claim:
1. A curable organopolysiloxane which contains at least one epoxy group and
has the average formula
##STR30##
wherein R.sup.1 is the same or different in the molecule and represents an
alkyl group with 1 to 4 carbon atoms, with the proviso that at least 90%
of the R.sup.1 groups are methyl groups,
R.sup.2 is selected from
a) an alkyl group with 1 to 20 carbon atoms, aryl group or aralkyl group,
b) an epoxy group which is linked by way of an Si-C bond to a silicon atom
of the polysiloxane, or
c) a group of the formula --R.sup.3 OH, wherein R.sup.3 is a divalent
alkylene group with 3 to 11 carbon atoms
a has a value of 1 to 1,000 and
b has a value of 0 to 10, with the proviso that in the average
organopolysiloxane molecule, at least one R.sup.2 groups has the meaning
b) and one the meaning c).
2. The polysiloxane of claim 1, in which R.sup.3 is a divalent alkylene
group with 3 to 6 carbon atoms.
3. The polysiloxane of claim 2, in which a has a value of 5 to 200 and b a
value of 0 to 2.
4. The polysiloxane of claim 2 in which b has a value of 0.
5. The polysiloxane of claim 1, in which R.sup.1 represents the methyl
group.
6. The polysiloxane of claim 2, in which R.sup.1 represents the methyl
group.
7. A method for the synthesis of the polysiloxane of claim 1, comprising
reacting an organopolysiloxane with a mixture of epoxides which have
terminal olefinic bonds and a compound of the formula R.sup.5 OH, wherein
R.sup.5 is an alkylene group with a terminal olefinic double bond and
contains 3 to 11 carbon atoms, in the presence of a catalyst capable of
catalyzing the reaction between said organopolysiloxane and said mixture
of epoxides and optionally in the presence of an inert solvent, at
temperatures of 50.degree. to 150.degree. C. in such quantitative
relationship, that the resultant epoxysiloxane has at least one --R.sup.3
OH group in the average molecule, wherein the organopolysiloxane is of the
average formula
##STR31##
wherein R.sup.1 is the same or different in the molecule and represents an
alkyl group with 1 to 4 carbon atoms, with the proviso that at least 90%
of the R.sup.1 groups are methyl groups,
R.sup.4 is selected from
a) an alkyl group with 1 to 20 carbon atoms, aryl group or aralkyl group,
b) an epoxy group which is linked by way of an SiC bond to a silicon atom
or the polysiloxane, or
c) a hydrogen atom
a has a value of 1 to 1,000 and
b has a value of 0 to 10,
with the proviso that in the average organopolysiloxane molecule, at least
one R.sup.4 group has the meaning a) and at least one the meaning c).
8. A method for synthesizing the polysiloxane of claim 1, comprising
reacting an organopolysiloxane with a mixture of epoxides which have
terminal olefinic double bonds and compounds of the formula R.sup.5 OH,
wherein R.sup.5 is an alkylene group with a terminal iolefinic double bond
which has 3 to 11 carbon atoms, in the presence of a catalyst capable of
catalyzing the reaction between said organopolysiloxane and said mixture
of epoxides and optionally, in the presence of an inert solvent at
temperatures of 50.degree. to 150.degree. C. and in such quantitative
ratio that the resultant polysiloxane has at least one epoxy group and at
least one --R.sup.3 OH group in the average molecule, wherein the
organopolysiloxane reactant is of the average formula
##STR32##
wherein R.sup.1 is the same or different in the molecule and represents an
alkyl grou8p with 1 to 4 carbon atoms, with the proviso that at least 90%
of the R.sup.1 groups are methyl groups,
R.sup.4 is selected from
a) an alkyl group with 1 to 20 carbon atoms, aryl group or aralkyl group,
or
b) a hydrogen atom
a has a value of 1 to 1,000 and
b has a value of 0 to 10,
with the proviso that in the average organopolysiloxane molecule, at least
two R.sup.4 groups represent hydrogen atoms.
9. A method of preparing a substrate with a curable coating having abhesive
properties comprising coating the substrate with an organopolysiloxane
defined in claim 1.
10. A method of preparing a substrate with a curable coating having
abhesive properties comprising coating the substrate with a mixture of an
organopolysiloxane defined in claim 1 and another organopolysiloxane which
has epoxy groups and which is free of --R.sup.3 OH groups.
11. A casting composition comprising the organopolysiloxane defined in
claim 1 in admixture with another organopolysiloxane which has epoxy
groups and which is free of --R.sup.3 OH groups.
12. A method of coating glass fibers comprising applying an
organopolysiloxane defined in claim 1 to the glass fibers.
13. A method of coating glass fibers comprising applying a mixture of the
organopolysiloxane defined in claim 1 and another organopolysiloxane which
has epoxy groups and which is free of --R.sup.3 OH groups to the glass
fibers.
14. The method according to claims 7 or 8, wherein the catalyst is selected
from the group consisting of H.sub.2 PtCl.sub.6, (NH.sub.3).sub.2
PtCl.sub.2 and Pt-carbon.
Description
BACKGROUND OF THE INVENTION
This invention relates to curable organopolysiloxanes having epoxy groups.
This invention also relates to a method for synthesizing these curable
organopolysiloxanes having epoxy groups and to the use thereof as curable
coating materials with abhesive properties, as casting compositions and as
coating materials for glass fibers.
There is extensive patent literature which deals with curable
epoxysiloxanes and their use as coating agents. Of the large number of
patents, U.S. Pat. No. 4,313,988 is named initially. In this patent, a
product is described which consists of a support tape with a
pressure-sensitive adhesive. On one side of the tape, a layer of a
normally adhering and pressure-sensitive adhesive is provided and on the
other surface, a material with abhesive properties is disposed. This
material consists of a curable epoxypolysiloxane either in solution or in
100% form, which corresponds to the formula
##STR1##
In this formula
R represents a low molecular weight alkyl group with 1 to 3 carbon atoms;
R.sup.1 represents a monovalent hydrocarbon group with 4 to 20 carbon
atoms;
E is a monovalent hydrocarbon group containing epoxy groups;
M is a silyl group having the formula R.sub.3 Si--; R.sub.2 R.sup.1 Si--or
R.sub.2 ESi--, R, R.sup.1 and E being as defined above;
a has a value of 5 to 200;
b is 0 or has a value up to 20% that of a and a +b is 5 to 200;
c can assume the value 0 when M is the R.sub.2 ESi group, or is larger than
0 but smaller than 20% of the value of a+b when M is the R.sub.3 Si--,
R.sub.2 R.sup.1 Si--or R.sub.2 ESi--group and
n has a value of 1 to 75,
with the proviso that the monovalent hydrocarbon group E, which contains
epoxy groups, contains at least one polymerizable epoxy group of the
formula
##STR2##
The rest of the E group consists of carbon and hydrogen atoms and is free
of acetylenic unsaturations. In addition to the oxiran ether oxygen, a
carbonyl oxygen or the
##STR3##
group can be present.
Also, the preparation can contain up to 98% by weight, based on
epoxypolysiloxane, of an epoxysilane.
It is pointed out in the aforementioned U.S. Pat. No. 4,313,988 that,
according to the state of the art, coatings with abhesive properties, that
is, with release properties towards adhesives, are widely used.
Dimethylpolysiloxanes provide coatings from which an adhesive tape can be
pulled off with the low release force of 4 to 16 g/cm of tape width This
measure indicates the force which must be employed to pull a 1 cm wide
adhesive tape from the abhesively finished surface. If, however, adhesive
tapes are to be produced, for example, in roll form and to be finished
abhesively, this degree of abhesiveness is too high, since it leads to
instabilities of the coiled roll. For such purposes, coatings are desired,
the release forces of which, with respect to adhesive tapes, are selective
and can be increased, for example to 60 to 350 g/cm and particularly to
about 60 to 200 g/cm.
The epoxysiloxanes contain at least one polymerizable epoxy group of the
formula
##STR4##
The following can be named as examples of such epoxy groups:
##STR5##
The epoxy groups preferably are located terminally at the hydrocarbon
group.
Preferred epoxypolysiloxanes of U.S. Pat. No. 4,313,988 are those of the
formula
##STR6##
wherein R is a methyl group, b has a value of 0 and the E group is a
.beta.-(3,4-epoxycyclohexyl)ethyl or a .gamma.-glycidoxypropyl group.
Curing of epoxypolysiloxanes or preparations which contain such
epoxypolysiloxanes is accomplished by addition and in the presence of
conventional epoxy curing catalysts. Examples of such catalysts are
tertiary amines, Lewis acids, such as BF.sub.3, and their complexes, such
as those with ethers or amines, and polyaromatic iodonium and sulfonium
complex salts, which contain SbF.sub.6 --or BF.sub.4 --anions as anions.
Organic acids and their salts or derivatives can also be used as curing
agents, such as perfluorinated sulfonic acids.
Suitable curing agents are also described in U.S. Pat. Nos. 4,394,403 and
4,310,469.
Very frequently, however, when adding the curing agent, it is observed
that, depending on the structure of the preparation and particularly of
the siloxanes, the miscibility and solubility of the photoinitiators
(curing agents) are limited. Epoxy-functional siloxanes have already been
modified in order to improve their compatibility with onium salt
photoinitiators. For Example, in EP-A-0 334 068, epoxy-functional
siloxanes are described, a portion of the epoxy groups of which was
esterified by reaction with aromatic acids, such as benzoic acid, or
unsaturated acids, such as acrylic acid. By these means, the compatibility
of the epoxysiloxanes with the curing catalysts was increased. At the same
time, however, the content of curable epoxy groups was decreased. Epoxy
groups are reactive groups which can be activated to polymerize by weaker
acids. This makes it exceedingly difficult to control the reaction. In the
extreme case, the reaction can become uncontrolled and lead to gelling.
Moreover, residual acid contents must be eliminated in order to ensure a
long shelf life.
In European publication 0 335 381, an organopolysiloxane with modified
release behavior and having the general R.sub.a R.sup.1.sub.b
SiO.sub.(4-a-b)/2 is described. In this formula, R is a hydrogen group, an
alkyl group with 1 to 8 carbon atoms or an aryl group. R.sup.1 is a
monovalent phenolic group with 6 to 26 carbon atoms; a is 0, 1 or 2; b is
1, 2 or 3 and a+b is 1, 2 or 3. The organopolysiloxane furthermore
contains units of the formula R.sub.a R.sup.2.sub.c SiO.sub.(4-a-b)/2' in
which R and a are defined as above. R.sub.2 is a hydrogen group, a
monovalent organofunctional acrylic group or a monovalent organofunctional
epoxy group; c is 1, 2 or 3 and a+b is 1, 2 or 3. The release power of
such a siloxane is modified by the amount of monovalent phenolic groups
contained. The higher the content of phenolic groups, the lower are the
release properties of the siloxane. However, as a result of the high
acidity of the phenolic hydroxyl group, considerable problems arise with
the synthesis and storage of these modified siloxanes. The epoxy groups
can be activated to polymerize by the phenolic OH group and this leads to
unwanted gelling and premature curing of the modified siloxanes.
SUMMARY OF THE INVENTION
It is an object of the invention to provide curable organopolysiloxanes
which contain epoxy groups and have good compatibility with
photoinitiators, without having the disadvantages mentioned above.
Another object of the invention is to provide modified epoxysiloxanes with
improved adhesion to the substrate and, at the same time, to provide an
opportunity for modifying the release properties in accordance with the
application, that is, to adjust them for the purpose for which they are
intended.
A further object of the invention is to provide a method for the synthesis
of epoxypolysiloxanes having the desired characteristics.
Another important object of the invention is the provision of a method of
using the organopolysiloxanes of the invention having epoxy groups, alone
or in admixture with other compounds, as a curable coating material with
abhesive properties, as a casting composition and as a casting material
for glass fibers.
These and other objects of the invention are attained by the invention
described below.
It has now been discovered that modified organopolysiloxanes which are
built up in a particular manner and contain epoxy groups have the desired
characteristics. Curable organopolysiloxanes of the invention which
contain epoxy groups have the average formula
##STR7##
wherein R.sup.1 is the same or different in the molecule and represents an
alkyl group with 1 to 4 carbon atoms, with the proviso that at least 90%
of the R.sup.1 groups are methyl groups,
R.sub.2 is selected from
a) an alkyl group with 1 to 20 carbon atoms, aryl group or aralkyl groups,
b) an epoxy group which is linked by way of an Si-C bond to a silicon atom
of the polysiloxane,
c) a group of the formula --R.sub.30 H, wherein R.sub.3 is a divalent
alkylene group with 3 to 11 carbon atoms
a has a value of 1 to 1,000 and
b has a value of 0 to 10,
with the proviso that in the average organopolysiloxane molecule, at least
one R.sub.2 group has the meaning b) and one the meaning c).
DESCRIPTION OF THE INVENTION
It is an essential characteristic of the inventive organopolysiloxanes
that, aside from epoxy groups which are linked by way of Si--C bonds with
silicon atoms of the polysiloxane, groups having the formula --R.sub.30 H
must be present. These --R.sub.3 OH groups are also linked to silicon
atoms of the polysiloxane. The --R.sub.3 OH groups intervene in the curing
mechanism and affect the release properties and the adhesion to the
substrate. Conventional photoinitiators, such as
di-(dodecylphenyl)iodonium hexafluoroantimonate, can be dispersed or
dissolved better in the inventive organopolysiloxanes having epoxy groups.
The significance of the groups and subscripts is explained in greater
detail below.
R.sup.1 can be the same or different within the average polysiloxane
molecule, R.sup.1 representing alkyl groups with 1 to 4 carbon atoms. At
least 90% of the R.sup.1 groups and preferably 100% of the R.sup.1 groups
are methyl groups.
The R.sub.2 groups can represent alkyl groups with 1 to 20 carbon atoms,
aryl groups or aralkyl groups. As alkyl groups, linear alkyl groups are
preferred. Examples of suitable alkyl groups are the methyl, ethyl,
propyl, butyl, hexyl, octyl, decyl and hexadecyl group. As an aryl group,
the phenyl group is preferred and as aralkyl, the benzyl group By suitably
selecting the alkyl groups, the release properties of the
organopolysiloxanes having epoxy groups can be affected and adapted for
the particular adhesive towards which they are to develop release
properties As the number of carbon atoms of the R.sub.2 groups increases,
the compatibility of the organopolysiloxanes with organic adhesives
improves and their release properties generally are reduced.
R.sub.2 furthermore represents epoxy groups which are linked by way of
Si--C bonds to silicon atoms of the polysiloxane. As examples of such
epoxy groups, reference is made to the initially described epoxy groups.
Particularly preferred epoxy groups are:
##STR8##
The R.sub.2 groups can be selected also from a group of formula --R.sub.3
OH, wherein R.sub.3 is a divalent alkylene group with 3 to 11 carbon
atoms. Preferably R.sub.3 is a divalent alkylene group with 3 to 6 carbon
atoms. This arises from the accessibility of the groups.
In the average organopolysiloxane molecule of the invention, one R.sub.2
must represent an epoxy group and at least one R.sub.2 group must
represent an --R.sub.3 OH group.
Subscript a indicates the number of difunctional siloxy units and has a
value of 1 to 1,000 and preferably 5 to 200.
The subscript b indicates the number of trifunctional siloxy units. It is
thus a measure of branching and has a value of 0 to 10 and particularly of
0 to 2 in the average molecule. Since linear organosiloxanes are
preferred, b particularly has a value of 0.
Organopolysiloxanes of the invention having epoxy groups are preferred
which contain on the average 2 to 30 epoxy groups and 1 to 10 --R.sub.3 OH
groups. Particularly preferred are organopolysiloxanes with 2 to 10 epoxy
groups and i to 5 --R.sup.3 OH groups.
Examples of suitable curable organopolysiloxanes of the invention having
epoxy groups are:
##STR9##
In the most recent European patent application, EP-A-0 391 162 A2, a
photopolymerizable preparation for coating is claimed, which contains, as
component (A), an epoxy-functional diorganopolysiloxane of the general
formula
R.sub.2 R'SiO(RR'SiO).sub.x SiR.sub.2 R'
wherein
R is an alkyl group with 1 to 8 carbon atoms,
R' is R or a monovalent, epoxy-functional organic group with 2 to 20 carbon
atoms, with the proviso that at least two R' groups are monovalent,
epoxy-functional organic groups and
x has a value of 0 to 20.
Only those inventive compounds in which subscript b has a value of 0 are
comparable with the compounds of this most recent European patent
application. Even then, however, the inventive compounds are distinguished
from the epoxy-functional siloxanes of the EP-A-0 391 162 A2, due to the
condition that in the average molecule one R.sub.2 group must be an
R.sub.3 --OH group. This condition is essential, however, to achieve the
aimed for properties.
A further object of the invention, which is a method for the synthesis of
the inventive polysiloxanes containing epoxy groups, is achieved by
reacting an organopolysiloxane with a compound of formula R.sup.5 OH,
wherein R.sup.5 is an alkylene group with a terminal olefinic double bond
and contains 3 to 11 carbon atoms, in the presence of a catalyst and
optionally in the presence of an inert solvent, at a temperature of
50.degree. to 150.degree. C. and in such a quantitative relationship that
the epoxysiloxane has at least one --R.sub.3 OH group in the average
molecule, wherein the organopolysiloxane is of the formula
##STR10##
wherein R.sup.1 in the molecule is the same or different and represents an
alkyl group with 1 to 4 carbon atoms, with the proviso that at least 90%
of the R.sup.1 groups are methyl groups,
R.sub.4 is selected from:
a) an alkyl group with 1 to 20 carbon atoms, aryl group or aralkyl group,
b) an epoxy group which is linked by way of Si--C bonds with silicon atoms
of the polysiloxane and
c) a hydrogen atom,
a has a value of 1 to 1,000 and
b has a value of 0 to 1,
with the proviso that in the average molecule, at least one R.sub.4 has the
meaning a) and at least one the meaning c).
The introduction of the --R.sub.3 OH group accordingly is accomplished by
an addition reaction between appropriate alcohols with a terminal olefinic
double bond and an organopolysiloxane having epoxy groups and,
additionally, SiH groups. This addition reaction is carried out in the
presence of a hydrosilylation catalyst, particularly platinum catalysts
such as H.sub.2 PtCl.sub.6, (NH.sub.3).sub.2 PtCl.sub.2 or platinum on
charcoal. The reaction is optionally and preferably carried out in the
presence of an inert solvent. An example of such an inert solvent is
toluene or xylene. The conversion takes place at temperatures from
50.degree. to 150.degree. C.
A further method for synthesizing inventive polysiloxane is characterized
in that an organopolysiloxane of the general average formula
##STR11##
wherein R.sup.1 in the molecule is the same or different and represents an
alkyl group with 1 to 4 carbon atoms, with the proviso that at least 90%
of the R.sup.1 groups are methyl groups,
R.sub.4 is selected from:
a) an alkyl group with 1 to 20 carbon atoms, aryl group or aralkyl group,
b) a hydrogen atom,
a has a value of 1 to 1,000 and
b has a value of 0 to 1,
with the proviso that in the average organopolysiloxane molecule, at least
two R.sup.4 groups represent hydrogen atoms, is reacted with a mixture of
epoxides which have terminal olefinic double bonds and compounds of the
formula R.sup.5 OH, wherein R.sup.5 is an alkylene group with a terminal
olefinic double bond, which has 3 to 11 carbon atoms, in the presence of a
catalyst and optionally in the presence of an inert solvent, at a
temperature of 50.degree. to 150.degree. C. and in such quantitative ratio
that the organopolysiloxane has at least one epoxy group and at least one
--R.sup.3 OH group in the average molecule.
The reaction is carried out in the same manner as described above.
A further object of the invention is the method of using the
organopolysiloxanes of the invention alone or in admixture with compounds
having epoxy groups, particularly epoxypolysiloxanes which are free of
--R.sup.3 OH groups, as curable coating materials with abhesive
properties, as casting compositions, particularly for electrical and
electronic purposes, and as coating materials for glass fibers.
The organopolysiloxanes of the invention can be used particularly as
coatings which develop release properties towards pressure-sensitive
adhesives of labels, decorative laminates, transfer papers and transfer
tapes. They can, moreover, be used as nonadhering packing materials for
foods and as industrial packing materials. In particular, paper sheets or
films of polyethylene, polypropylene or polyester serve as support sheets
for the abhesive coatings.
The inventive organopolysiloxanes can be used to advantage for the
production of printing inks and decorative coatings.
A further preferred use for the organopolysiloxanes of the invention is the
employment thereof alone or in admixture with other curable compounds as
casting compositions. These casting compositions are employed particularly
for electrical or electronic components, such as printed circuit board
assemblies, switching devices, plugs, etc., which are exposed to the
effects of aggressive media, moisture, etc.
The compounds of the invention and mixtures thereof can also be used to
coat glass fibers which are intended, particularly, for the manufacture of
beam waveguides. The coating protects the glass fibers against damage and
damaging external influences and at the same time, affects the reflection
of the glass fibers.
The curable modified organopolysiloxanes of the invention having epoxy
groups can be used alone as curable coating materials, after the addition
of conventional photoinitiators in an amount of 0.01% to 7% by weight,
based on the organopolysiloxane. Optionally, these preparations can
contain solvents, so that they can be applied better. However,
solvent-free preparations are preferred. However, the organopolysiloxanes
of the invention can be added also to conventional organopolysiloxanes
which contain epoxy groups and represent the state of the art, in order to
affect and modify their properties during the common curing reaction.
The inventive organopolysiloxanes can be mixed with reactive or nonreactive
additives. Nonreactive additives are, for example, fillers or pigments,
such as aerosil, titanium dioxide and barium sulfate.
Reactive additives are cationically curable compounds, which can be cured
together with the inventive compounds and cross linked with these.
In the following examples, which further illustrate the best mode currently
contemplated for carrying out the invention, the synthesis of curable
modified organopolysiloxanes of the invention having epoxy groups is
described initially. In the subsequent application-related comparison
experiments, the properties of the inventive organopolysiloxanes are
compared with those of the state of the art. The examples of the invention
must not be construed as limiting the invention in any manner.
EXAMPLE 1
To a mixture of 496 g (4.0 moles) of vinylcyclohexene oxide, 154 g (2.6
moles) of allyl alcohol and 16 mg of H.sub.2 PtCl.sub.6.6H.sub.2 O at
120.degree. C., 1,942 g (1 mole) of a polydimethylsiloxane which contains
SiH groups and has the average formula
##STR12##
are added dropwise. At the end of the addition, stirring is continued for
a further 6 hours at 130.degree. C. After filtration and removal of the
volatile reaction products at 120.degree. C. and 0.1 mbar, 2,351 g (93% of
the theoretical yield) of a moderately viscous oil are obtained, which,
according to the IH-NMR spectrum, has the following general formula
##STR13##
wherein A.sup.1 is as defined for compound 1
A.sup.2 is as defined for compound 1
m=0.4.
EXAMPLE 2
As in Example 1, 376 g (3.3 moles) of allyl glycidyl ether, 191 g (3.3
moles) of allyl alcohol and 2,187 g of a polydimethylsiloxane containing
SiH groups (see Example 1) are reacted to form a polydimethylsiloxane of
the general formula
##STR14##
wherein A.sup.2 is as defined for compound 1
A.sup.5 is as defined for compound 5
n 0.5 and m 0.5.
EXAMPLE 3
As in Example 1, 50.0 g (0.4 moles) of vinylcyclohexene oxide, 15.3 g (0.26
moles) of allyl alcohol and 1,159 g (0.1 moles) of a polydimethylsiloxane,
which contains SiH groups and has the following general formula
##STR15##
are reacted to form a polydimethylsiloxane of the following general
formula
##STR16##
wherein A.sup.1 is as defined for compound 1
A.sup.2 is as defined for compound 1
N=0.6
m=0.4.
EXAMPLE 4
As in Example i, 49 g (0.7 moles) of butadiene monoepoxide, 2.9 g (0.15
moles) of 3-methyl-3-butene-1-ol and 1,156 g (0.05 moles) of a
polydimethylsiloxane, which contains Si-H groups and has the general
formula
##STR17##
are reacted to form a polydimethylsiloxane of the general formula
##STR18##
wherein A.sup.3 is as defined for compound 3
A.sup.4 is as defined for compound 3
n 0.83
m 0.17.
EXAMPLE 5
As in Example 1, 136.4 g (1.1 moles) of vinylcyclohexene oxide, 95.7 g (1.1
moles) of 3-methyl-3-butene-1-ol and 1,538 g (1 mole) of a
polydimethylsiloxane which contains SiH groups and has the average formula
##STR19##
are reacted to form a polydimethylsiloxane of the general formula
##STR20##
wherein A.sup.1 is as defined for compound 1
A.sup.4 is as defined for compound 3
n=0.5
m=0.5.
EXAMPLE 6
As in Example 1, 231 g (3.3 moles) of butadiene monoepoxide, 95.7 g (1.1
moles) of a 3-methyl-3-butene-1-ol and 2,194 g (1 mole) of a
polydimethylsiloxane, which contains SiH groups, are reacted to form a
polydimethylsiloxane of the following average formula
##STR21##
wherein A.sup.3 is defined as for compound 3
A.sup.4 is defined as for compound 3
n=0.25
m=0.75.
EXAMPLE 7
As in Example 1, 115.9 g (0.9 moles) of vinylcyclohexene oxide, 24.8 g
(0.17 moles) of 8(9)-hydroxy-tricyclo[5.2.1.0.sup.2,6 ]-3decene and 494 g
(0.1 moles) of a polysiloxane, the average formula of which is
##STR22##
are reacted to form a siloxane of the general formula
##STR23##
wherein A.sup.1 is defined as for compound 1
A.sup.6 is defined as for compound 4
n=0.15
m=0.85.
EXAMPLE 8
As in Example 1, 115.9 g (0.9 moles) of vinylcyclohexene 24.8 g (0.17
moles) of 8(9)-hydroxy-tricyclo[5.2.1.0.sup.2,6 ]-3decene and 424 g (0.1
moles) of a polydimethylsiloxane, which contains Si-H groups, are reacted
to form a polydimethylsiloxane having the average formula
##STR24##
wherein A.sup.1 is defined as for compound 1
A.sup.6 is defined as for compound 4
n=0.15
m=0.85.
EXAMPLE 9
As in Example i, 68.2 g (0.55 moles) of vinylcyclohexene oxide, 55.4 g
(0.77 moles) of methallyl alcohol and 2,308 g of a polydimethylsiloxane
which contains Si-H groups are reacted to form a polydimethylsiloxane
having the average formula
##STR25##
wherein: A.sup.1 is defined as for compound 1
A.sup.7 is defined as for compound 5.
EXAMPLE 10
As in Example 1, 68.2 g (0.55 moles) of vinylcyclohexene oxide, 55.4 g
(0.77 moles) of methallyl alcohol and 2,798.2 g of a polydimethylsiloxane
which contains Si-H groups are reacted to form a polydimethylsiloxane
having the average formula
##STR26##
wherein: A.sup.1 is defined as for compound 1
A.sup.7 is defined as for compound 5.
EXPERIMENTAL EXAMPLES 1 to 3
Comparative Examples, not of the invention
As in Example 1, vinycylohexene oxide and polydimethyl-siloxanes, which
contain Si-H groups, are reacted to form polydimethylsiloxanes of the
following average formulas:
Experimental Example 1
##STR27##
Experimental Example 2
##STR28##
Experimental Example 3
##STR29##
Application Tests of Compositions of the Invention and of Comparative
Examples
To check the application properties of the polysiloxanes modified pursuant
to the invention, compounds 1 to 10 are mixed with 1% by weight of
bis(dodecylphenyl)iodonium hexafluoroantimonate, applied on an oriented
polypropylene film and cured with a Fusion UV lamp (120 W/cm). The amount
applied in each case is about I.i g/cm.sup.2. For the comparison examples,
different 80 mm wide adhesive tapes are used, namely adhesive tapes coated
with acrylate adhesives, which are obtainable commercially under the names
Of Tesa.RTM. 154 and Tesa.RTM. 970, as well as an adhesive tape coated
with a rubber adhesive, which is obtainable commercially under the name of
Tesa.RTM. 969.
To measure the abhesiveness, the adhesive tapes are rolled onto the
substrate and stored subsequently, in the case of the acrylate adhesive
tapes at 70.degree. C. and in the case of the rubber adhesive tapes at
40.degree. C. After 24 hours, the force is measured, which is required to
pull the respective adhesive tape from the substrate at a peel angle of
180.degree.. This force is referred to as the release force. In addition
the adhesion of the modified polysiloxanes to the substrate is checked by
rubbing vigorously with the thumb. Rubbery crumbs are formed if the
adhesion is defective (so-called rub off test).
TABLE
__________________________________________________________________________
Modified Siloxane Oriented Polypropylene Film
Epoxy
OH Tesa.sup.(R)
Tesa.sup.(R)
Tesa.sup.(R)
Solubility Surface
Chain
Function-
Function-
Alkyl
154 970 969 of Photo-
Rub Oily/
Length
ality
ality
Group
Release Force (N)
initiator
Off
Curing
greasy
__________________________________________________________________________
Example
1 27 3 2 ./. 2.1 2.5 2.6 very good
no yes no
2 27 2.5 2.5 ./. 2.4 2.7 2.8 very good
no yes no
3 157 3 2 ./. 0.3 0.38
0.35
good no yes no
4 314 10 2 ./. 0.15
0.1 0.12
moderate
no yes no
5 21 1 1 ./. 2.0 2.3 2.2 good no yes no
6 ./. 3 1 ./. 3.2 3.8 6.5 good no yes no
7 59 6.8 1.2 C.sub.6 H.sub.13
2.1 2.4 2.2 good no yes no
8 59 6.8 1.2 ./. 1.8 1.7 1.9 good no yes no
9 314 5 7 ./. 0.05
0.08
0.07
good no yes no
10 314 5 7 C.sub.8 H.sub.17
0.15
0.2 0.19
good no yes no
Experimental
Example
1 27 5 0 ./. 1.9 2.2 2.2 moderate
yes
yes no
2 25 3 0 ./. ./. ./. ./. poor ./.
no yes
3 155 3 0 ./. ./. ./. ./. very poor
./.
no no
__________________________________________________________________________
It follows from the data in the Table that the organopolysiloxanes which
have been modified pursuant to the invention have the desired application
properties. They show good adhesion to the support, can be cured rapidly,
show good abhesive properties towards adhesives of chemically different
structures, in contrast to the organopolysiloxanes of the state of the
art, can be adapted to the chemical character of the adhesive by choosing
suitable substituents while keeping the siloxane framework the same and
show good compatibility with photoinitiators. It is particularly striking
that the organopolysiloxanes which have been modified pursuant to the
invention still cure readily despite a lower epoxy functionality. This is
due to a synergism between the epoxy group and the R.sub.3 --OH group.
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